US-12618970-B2 - Object detection device, object detection method, and recording medium

US12618970B2US 12618970 B2US12618970 B2US 12618970B2US-12618970-B2

Abstract

An object detection device includes an acquisition circuit, a calculation circuit, and an estimation circuit. The acquisition circuit acquires elapsed times from when an ultrasonic wave is transmitted from a transmission microphone to when reception microphones each receive the ultrasonic wave. The calculation circuit calculates a wind speed on the basis of the elapsed times acquired by the acquisition circuit. The estimation circuit estimates a vehicle state on the basis of the wind speed calculated by the calculation circuit.

Inventors

Takahiro Shima
Tadashi Morita

Assignees

PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20231114
Priority Date: 20230228

Claims (19)

1 . An object detection device configured to be mounted on a vehicle, the object detection device comprising: an acquisition circuit which, in operation, acquires elapsed times from when an ultrasonic wave is transmitted from a transmission microphone to when reception microphones each receive the ultrasonic wave; a calculation circuit which, in operation, calculates a wind speed based on the elapsed times acquired by the acquisition circuit; and an estimation circuit which, in operation, estimates a traveling direction of the vehicle based on the wind speed calculated by the calculation circuit.
2 . The object detection device according to claim 1 , wherein a number of the reception microphones is a multiple of 2.
3 . The object detection device according to claim 1 , wherein the reception microphones are provided on a side face of a vehicle, the reception microphones being arranged in a horizontal direction of the vehicle while interposing the transmission microphone between the reception microphones.
4 . The object detection device according to claim 1 , wherein the reception microphones are provided on a front face of a vehicle, the reception microphones being arranged in a vertical direction of the vehicle while interposing the transmission microphone between the reception microphones.
5 . The object detection device according to claim 1 , wherein a number of the reception microphones is a multiple of 4, and the reception microphones are disposed to surround the transmission microphone.
6 . The object detection device according to claim 1 , wherein the calculation circuit which, in operation, performs calculation of the wind speed by using a time difference between the elapsed times acquired by the acquisition circuit.
7 . The object detection device according to claim 1 , further comprising a transmission control circuit which, in operation, controls transmission of ultrasonic wave performed by the transmission microphone in accordance with the traveling direction of the vehicle estimated by the estimation circuit.
8 . The object detection device according to claim 1 , further comprising a reception control circuit which, in operation, controls reception of ultrasonic wave performed by the reception microphones in accordance with the traveling direction of the vehicle estimated by the estimation circuit.
9 . An object detection method by an object detection device configured to be mounted on a vehicle, the method comprising: acquiring elapsed times from when an ultrasonic wave is transmitted from a transmission microphone to when reception microphones each receive the ultrasonic wave; calculating a wind speed based on the elapsed times acquired by the acquiring; and estimating a traveling direction of the vehicle based on the wind speed calculated by the calculating.
10 . The object detection method according to claim 9 , wherein a number of the reception microphones is a multiple of 2.
11 . The object detection method according to claim 9 , wherein the reception microphones are provided on a side face of a vehicle, the reception microphones being arranged in a horizontal direction of the vehicle while interposing the transmission microphone between the reception microphones.
12 . The object detection method according to claim 9 , wherein the reception microphones are provided on a front face of a vehicle, the reception microphones being arranged in a vertical direction of the vehicle while interposing the transmission microphone between the reception microphones.
13 . The object detection method according to claim 9 , wherein a number of the reception microphones is a multiple of 4, and the reception microphones are disposed to surround the transmission microphone.
14 . The object detection method according to claim 9 , wherein the calculating of the wind speed is performed by using a time difference between the elapsed times acquired by the acquiring.
15 . The object detection method according to claim 9 , further comprising controlling transmission of ultrasonic wave performed by the transmission microphone in accordance with the traveling direction of the vehicle estimated by the estimating.
16 . The object detection method according to claim 9 , further comprising controlling reception of ultrasonic wave performed by the reception microphones in accordance with the traveling direction of the vehicle estimated by the estimating.
17 . A non-transitory computer-readable recording medium on which programmed instructions are recorded, the programmed instructions causing a computer configured to be mounted on a vehicle to execute processing, the processing comprising: acquiring elapsed times from when an ultrasonic wave is transmitted from a transmission microphone to when reception microphones each receive the ultrasonic wave; calculating a wind speed based on the elapsed times acquired by the acquiring; and estimating a traveling direction of the vehicle based on the wind speed calculated by the calculating.
18 . The object detection device according to claim 7 , wherein: the estimation circuit, in operation, further estimates a speed of the vehicle based on the wind speed calculated by the calculation circuit; in a case that the traveling direction of the vehicle estimated by the estimation circuit is forward and the speed of the vehicle estimated by the estimation circuit is lower than a predetermined value, a transmission control circuit, in operation, reduces a wave number of the ultrasonic wave transmitted from the transmission microphone and reduces an output level of the ultrasonic wave; and in a case that the traveling direction of the vehicle estimated by the estimation circuit is forward and the speed of the vehicle estimated by the estimation circuit is not less than the predetermined value, the transmission control circuit, in operation, increases the wave number of the ultrasonic wave transmitted from the transmission microphone and increases the output level of the ultrasonic wave.
19 . The object detection method according to claim 9 , further comprising: estimating a speed of the vehicle based on the wind speed calculated by the calculating; reducing a wave number of the ultrasonic wave transmitted from the transmission microphone and an output level of the ultrasonic wave, in a case that the traveling direction of the vehicle by the estimating is forward and the speed of the vehicle by the estimating is lower than a predetermined value; and increasing the wave number of the ultrasonic wave transmitted from the transmission microphone and the output level of the ultrasonic wave, in a case that the traveling direction of the vehicle by the estimating is forward and the speed of the vehicle by the estimating is not less than the predetermined value.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2023-029179, filed on Feb. 28, 2023, the entire contents of which are incorporated herein by reference. FIELD The present disclosure relates generally to an object detection device, an object detection method, and a recording medium. BACKGROUND As an existing method of transmission and reception control for ultrasonic sensors, there is technology in which a transmission and reception controller provided in an electronic control unit (ECU) changes transmission and reception timings of an ultrasonic sensor on the basis of vehicle information (traveling forward, traveling backward, the vehicle speed, etc.) (see, for example, JP 2016-085036 A). For example, at the time of traveling forward, an ultrasonic sensor facing in the traveling direction is operated to transmit detection data to the ECU. In such an existing technology, examination on increasing the number of ultrasonic sensors connected to an ECU is insufficient. SUMMARY An object detection device according to the present disclosure includes an acquisition circuit, a calculation circuit, and an estimation circuit. The acquisition circuit is configured to acquire elapsed times from when an ultrasonic wave is transmitted from a transmission microphone to when reception microphones each receive the ultrasonic wave. The calculation circuit is configured to calculate a wind speed on the basis of the elapsed times acquired by the acquisition circuit. The estimation circuit is configured to estimate a vehicle state on the basis of the wind speed calculated by the calculation circuit. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for describing a related art; FIG. 2 is a diagram for describing the related art; FIG. 3 is a diagram illustrating a configuration example of an object detection device according to an embodiment; FIG. 4 is a diagram for describing calculation of a wind speed by the object detection device according to the embodiment; FIGS. 5A and 5B are diagrams for describing locations of reception units according to the embodiment; FIGS. 6A and 6B are diagrams for describing estimation of a vehicle state by the object detection device according to the embodiment; FIGS. 7A to 7C are diagrams for describing a threshold value used for estimation of a vehicle state; FIGS. 8A to 8D are diagrams for describing changing a transmission pattern by the object detection device according to the embodiment; FIGS. 9A and 9B are diagrams illustrating a configuration example of an object detection device according to an embodiment; FIGS. 10A to 10C are diagrams for describing changing a reception band by the object detection device according to the embodiment; FIG. 11 is a flowchart illustrating an example of a procedure of determination processing according to the embodiment; and FIG. 12 is a diagram illustrating an example of a hardware configuration of a control device according to the embodiment. DETAILED DESCRIPTION Hereinafter, embodiments of an object detection device 1 according to the present disclosure will be described with reference to the drawings. In the following, an example in which the object detection device 1 is mounted on a vehicle will be described, whereas it is not limited thereto. 1. Introduction As illustrated in FIG. 1 for a related art, a sonar module is mounted on a vehicle or the like to detect an obstacle by using an ultrasonic wave. The sonar module communicates with an ECU and is controlled on the basis of vehicle information representing traveling forward, traveling backward, or the vehicle speed acquired from the ECU. However, it is difficult for the sonar modules to handle an increase in the number of sensors. For example, in a case where the number of sonar modules mounted on a vehicle increases, the communication band used between an ECU and the sonar modules becomes insufficient, and it becomes difficult to perform stable control. Moreover, in a case of causing the sonar modules to autonomously operate, communication with the ECU is not performed. Therefore, it is difficult to change the behavior of various sensors on the basis of the vehicle information. In addition, in the existing technology, the transmission and reception controller of the ultrasonic sensor is provided inside the ECU as illustrated in FIG. 2. Therefore, there is a possibility that transmission and reception of the ultrasonic sensor becomes difficult when the ECU is changed to have different specifications. Therefore, in order for the ultrasonic sensor to perform transmission and reception control without depending on the ECU specifications, it is desirable that the ultrasonic sensor itself can perform autonomous operation to perform transmission and reception control. Considering the above, an embodiment of the present disclosure performs processing that includes: calculating the wind speed as a speed at which